The present invention generally relates to computer input devices, namely those which require the interaction between user, arm, and hand including mice, joysticks, and pens. The disclosed invention attempts to reestablish the true meaning of an ergonomic device as that which induces a low biomechanical load on the user. Specifically, biomechanically low load is in reference to the human arm, hand in coordination with the current invention.
Conditions of low load, regarding physical human movement, can be derived of two components: the physical structure and “grip” required of the arm and hand by the device, as well as the motion of the hand and arm system required described in both magnitude and form. Low load, with regards to the “grip” of the hand is known within the art as deviance from the rest position of the arm and hand. The rest position is known to be the structure of the arm and hand in a standing position, not tensed and unaffected. The rest position of the hand can be described, generally, as a handshake position, with thumbs and fingers facing downward, fingers curled pointing towards the body. This structure establishes the ideal ergonomic structure. However, prior art mice generally do not provide for mousing with the hand in an at rest position. Furthermore, the extent of physical deviation from this position may be known as strain.
As far as the motion of the hand and arm, several factors are derivative. First, it is known within the art that although some movement is necessary and beneficial over a period of time of usage, ideally, stress should be avoided throughout the fine motor control muscles of the lower hand, and preferably applied to the larger muscles of the upper arm.
It is with respect to these parameters that the current invention can be compared understandably over prior art. For instance, in U.S. Pat. No. 5,355,147 issued to Lear, a device of vertical orientation is taught. However, all fingers of the hand are required to grip the mouse. In addition, the wrist support inflects the hand in an upward motion. This invention induces strain on the user in both manners. The necessity to clench and support the mouse with all fingers, as well as the wrist support in an altering position, leads to a clear deviation from the ideal position previously described.
Additionally, U.S. Pat. No. 5,576,733 issued to Lo discloses an invention, which improves upon that of Lear by securely gripping the device, vertically, by consisting of a housing structure with two simple sides. One side allows for placement of the thumb as the other side allows for placement of the fingers. Control is improved by giving the user the ability to move the pointer by flexing either the thumb or fingers more so than the entire arm or wrist. Thus, the ideal arm and hand motion, as described earlier, is violated at the expense of better control.
Also known within the art are hand controller devices, such as U.S. Pat. No. 4,862,165 issued to Gart, which attempts to provide an “ergonomic” device. The '165 patent fails to provide support for the vertical orientation of the hand of the user. Thus, once again, the ideal low load position is violated.
Also known within the art, are devices known as trackballs and combinations of trackballs and mice. U.S. Pat. No. 6,292,175 issued to Sheehan discloses such a device. In this patent, Sheehan teaches a mouse similar to that Gart with respect to hand orientation. However, a trackball is provided to negate the necessity for large arm and wrist movements. This, however, gives rise to repetitive, lengthy use of the weak muscles of the thumb and fingers and creates torque within the lower arm due to the lack of a vertical orientation.
Another problem with prior art mousing devices is the requirement to purchase separate mousing devices for left and right handed individuals. This can be expensive for houses in which there are both left and right handed users of a single computer. Also, for public spaces (such as public libraries) it is desirable to provide a biomechanically low load computer mouse that can be used by all users.
As can be seen, there is a need within the art for a hand controlled pointing device, which truly performs at a low load level, significantly reducing high statistics rates of damaged muscle tissue and severe injury. Also, a mouse that can be adjusted between left and right handed devices. There is also a need for a hand pointing device which can adjust to the varying hand structure of different users. Additionally, there is a need for a device which may apply contour in effective areas, and support the hand in such a way that strain is concentrated on the larger muscles of the lower arm rather than specific muscles of the wrist and fingers.